merb.intro

merb.intro :by => "Paul Barry" "Paul Barry"

What is Merb? A Ruby MVC Web Framework similar to Rails, but: • Small • Fast • Light • Less Opinionated

Create Your App $ merb-gen app blog ~/projects

Configure Your App config/init.rb use_orm :activerecord dependency "merb-action-args" dependency "merb-assets" dependency "merb-builder" dependency "merb-parts" dependency "merb_activerecord" dependency "merb_helpers"

Configure Your Database config/database.yml development: adapter: sqlite3 database: dev.db timeout: 5000 test: adapter: sqlite3 database: test.db timeout: 5000

Generate a Model $ merb-gen model article title:string body:text ~/projects/blog

Create the Table $ rake db:migrate ~/projects/blog

Create an Article $ merb -i >> article = Article.new(:title => 'First Post')‏ => #<Article id: nil...> >> article.body = 'Lorem ipsum dolor sit amet...' => "Lorem ipsum dolor sit amet..." >> article.save!=> true ~/projects/blog

Create a Controller app/controllers/articles.rb class Articles < Application def index "Hello, World!" end end

Create RESTful Route config/router.rb Merb :: Router .prepare do | r | r.resources :articles end

Start Merb $ merb ~/projects/blog

View the controller

Named Route config/router.rb r.match( "/sleep/:time" ).to( :controller => "sleeper" , :action => "execute" ).name( :sleeper )‏

Blocking Controller app/controllers/sleeper.rb class Sleeper < Application def execute (time = 5 )‏ sleep time.to_i "I slept for #{time} seconds" end end

Non-Blocking Controller app/controllers/sleeper.rb class Sleeper < Application def execute (time = 5 )‏ render_deferred do sleep time.to_i "I slept for #{time} seconds" end end end

Demo

Create a Real Action app/controllers/articles.rb class Articles < Application def index @articles = Article .find( :all , :limit => 5 , :order => "created_at desc" )‏ display @articles end end

Create the View app/views/articles/index.html.erb <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> <% throw_content :page_title , "Articles" %> <% throw_content :sidebar do %> <%= partial 'shared/me' %> <% end %> <%= partial 'article' , :with => @articles %>

Create the Partial app/views/articles/_article.html.erb <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> <div id= "article_ <%= article.id %> " class= "article" > <h2> <%= link_to h(article.title), url( :article , article) %> </h2> <p class= "posted_at" > Posted at <%= article.created_at.strftime "%l:%M %p" %> on <%= article.created_at.strftime "%A, %B %e" %> <p> <%= h(article.body) %> </p> </div>

Create the Shared Partial app/views/shared/_me.html.erb <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> <h2> About Me </h2> <%= image_tag "me.jpg" %>

Create the Layout app/views/layout/articles.html.erb <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> <html> <head> <title> Merb Blog - <%= catch_content :page_title %> </title> <%= css_include_tag 'application' %> <%= catch_content :html_head %> </head> <body> <div id= "page" > <div id= "header" ><h1> Merb Blog </h1></div> <div id= "content" > <%= catch_content %> </div> <div id= "sidebar" > <%= catch_content :sidebar %> </div> </div> </body> </html>

View Articles

Create the Show Action app/controllers/articles.rb <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> def show (id)‏ @article = Article .find_by_id(id)‏ raise NotFound unless @article display @article end

Create the Show View app/views/show.html.erb <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> <% throw_content :page_title , h( @article .title) %> <% throw_content :sidebar do %> <%= partial 'shared/me' %> <% end %> <%= partial 'article' , :with => @article %>

View Article <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %>

Add RSS Mime Type config/init.rb <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> Merb .add_mime_type :rss , nil , %w[text/xml]

Add RSS to Provides app/controllers/articles.rb <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> class Articles < Application provides :rss def index @articles = Article .find( :all , :limit => 5 , :order => "created_at desc" )‏ display @articles end end

Create RSS Builder app/views/articles/index.rss.builder <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> xml.instruct! :xml , :version => "1.0" xml.rss :version => "2.0" do xml.channel do xml.title "Merb Blog" xml.description "The greatest blog in the world" xml.link " http://merb.blog " @articles .each do | a | xml.item do xml.title a.title xml.description a.body xml.pubDate a.created_at.to_s( :rfc822 )‏ xml.link url( :article , a)‏ xml.guid url( :article , a)‏ end end end end

Add Auto-Discovery Link app/views/articles/index.html.erb <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> <% throw_content :html_head do %> <link rel= "alternate" type= "application/rss+xml" title= "RSS" href= "/articles.rss" /> <% end %>

RSS Icon <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %>

RSS Feed <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %>

Create Recent Article Part <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %>

class RecentArticles < Merb::PartController

def index

@articles = Article .find( :all ,

:limit => params[ :limit ],

:order => 'created_at desc' )‏

render

end

end

app/parts/recent_articles.rb

Recent Article Part View <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> app/parts/views/recent_articles/index.html.erb <h2> Recent Articles </h2> <ul> <% @articles .each do | a | %> <li> <%= link_to h(a.title), url( :article , a) %> </li> <% end %> </ul>

Add Part to View <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> app/views/articles/show.html.erb <% throw_content :sidebar do %> <%= partial 'shared/me' %> <%= part RecentArticles => "index" , :limit => 5 %> <% end %>

Recent Articles <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %>

Generate Admin Controller <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> ~/projects/blog $ merb-gen resource_controller admin/articles create app/controllers/admin create app/helpers/admin create app/views/admin/articles create app/controllers/admin/articles.rb create app/helpers/admin/articles_helper.rb create app/views/admin/articles/edit.html.erb create app/views/admin/articles/index.html.erb create app/views/admin/articles/new.html.erb create app/views/admin/articles/show.html.erb

Add Admin Route <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> config/router.rb Merb :: Router .prepare do | r | r.namespace :admin do | admin | admin.resources :articles end r.resources :articles end

View Routes <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> ~/projects/blog $ merb -i >> merb.show_routes Named Routes edit_admin_article: /admin/articles/:id/edit delete_admin_article: /admin/articles/:id/delete article: /articles/:id admin_articles: /admin/articles new_article: /articles/new admin_article: /admin/articles/:id edit_article: /articles/:id/edit articles: /articles new_admin_article: /admin/articles/new delete_article: /articles/:id/delete

Admin Articles View <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> app/views/admin/articles/index.html.erb <h2> Articles </h2> <p> <%= link_to "Create New Article" , url( :new_admin_article ) %> <ul> <% @articles .each do | a | %> <li> <%= link_to h(a.title), url( :admin_article , a) %> </li> <% end %> </ul>

Admin New Article View <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> app/views/admin/articles/new.html.erb <h2> New Article </h2> <%= partial 'form' %>

Admin Edit Article View <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> app/views/admin/articles/edit.html.erb <h2> Edit Article </h2> <%= partial 'form' %>

Admin Article Form <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> app/views/admin/articles/_form.html.erb <%= error_messages_for :article %> <% form_for @article , :action => url( :admin_article , @article ) do %> <div class= "field" > <%= text_control :title , :label => 'Title' %> </div> <div class= "field" > <%= text_area_control :body , :rows => 20 , :cols => 80 %> <div> <div class= "buttons" > <%= submit_button 'Save' %> </div> <% end %>

Create a New Article <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %>

Admin Article View <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> app/views/admin/articles/show.html.erb <h2> <%=h @article .title %> </h2> <p> <%=h @article .body %> </p> <hr /> <%= link_to "Back to Articles" , url( :admin_articles ) %> | <%= link_to "Edit this Article" , url( :edit_admin_article , @article ) %>

So is it worth it?

Numbers <% throw_content :page_title, "Articles" %><%= partial 'article', :with => @articles %> min avg max stddev rails GET /articles 37.4 45.7 47.0 2.0 rails GET /articles/1 44.0 45.1 45.8 0.6 merb GET /articles 70.0 71.1 73.0 0.8 merb GET /articles/1 88.0 107.1 110.1 7.2 requests/second

Thank You! http://merbivore.com #merb on irc.freenode.net http://mwrc2008.conf reaks.com/02zygmuntowicz.html http://paulbarry.co m Resources